Beta-Testing the Mocktopus

Guest column by Nathan Forster

Welcome to the Mocktopus, our first attempt at a mock draft created through statistical analysis. The Mocktopus first estimates the probability that a given team "on the clock" will select a player from one of eleven position groups--quarterbacks, offensive tackles, running backs, wide receivers, tight ends, interior offensive linemen, interior defensive linemen, edge rushers (college defensive ends), linebackers who are not edge rushers, cornerbacks, and safeties. A separate model then estimates the probability that the team on the clock will select the first, second, third, or fourth "most valuable" player available at the position. Both of these estimates are conducted using a technique called logistic regression. Using software that I specifically designed to execute the models, the Mocktopus simulates the NFL Draft 10,000 times to create a mock draft.

The principal components in the Mocktopus are other mock drafts. Although mock drafts are frequently criticized for missing on their picks more often than they hit, they are nevertheless significantly more accurate than a chimpanzee pulling random names out of a hat. My research suggests that those who have had the most accurate mock drafts in the past can also be expected to produce above average mock drafts in the future, although their level of accuracy can be expected to drop somewhat. Thus, as part of its calculations, the Mocktopus assigns weights to mock drafts from the most successful draftniks based on historical accuracy, but it also assumes that the accuracy of their mock drafts will regress towards the mean in the future. The most historically accurate mock draft according to the model is Mike Mayock of NFL Network’s mock draft, and you will see his strong influence on the model.

The second component is a metric that measures value by combining the "Top 100" overall prospects lists from the Draft Countdown and NFL Draft Scout websites. Mock drafts tend to focus too much on team needs and not enough on prospect value, so including a metric for "value" helps control for a bias for pairing teams with low value players in order to address the teams' most critical needs. Moreover, when a team drafts a player at a position that few expect, it often does so at a position where good value is available (for instance, St. Louis' selection of Robert Quinn and Detroit's selection of Nick Fairley in the 2011 Draft). Interestingly, value was not a statistically significant factor as to quarterbacks and offensive tackles, which are positions highly-driven by team needs, and therefore the Mocktopus does not use value to predict whether a team will draft a quarterback or offensive tackle (although it does use value to help it predict which quarterback or offensive tackle will be drafted).

Finally, the Mocktopus also incorporates team performance variables that have been statistically significant predictors of player choice in past drafts. As to quarterbacks, the Mocktopus' predictor variables include the age of the team's projected starter (teams with old quarterbacks tend to draft new ones). As to wide receivers, the predictor variables include the collective yards per catch of the team's projected starting wide receivers (teams tend to draft wide receivers when they lack down-field threats on the roster). There are other team-based factors that barely missed the cut for inclusion in the Mocktopus because they approached, but were not, statistically significant (such as team sack rates for edge rushers) so there is definitely the potential to add additional team-based factors in the future.

Although this sounds silly to type, this project has also raised an oddly philosophical question about mock drafting: what is the purpose of a mock draft? I would imagine that most fans, when they read a mock draft, are most interested in the player that the mock draft projects for their favorite team.

However, traditional mock drafts are clearly not optimized for this purpose. An interesting discovery that I made while developing the Mocktopus is that creating a mock draft for the purpose of providing projections for thirty two separate fan bases almost invariably involves projecting the same player to multiple teams. This is a consequence of the fact that the probability that a team will select a particular player, given the team’s 100+ options, is typically well under 50 percent.

For instance, imagine that we think that the Cleveland Browns have a 35 percent chance of drafting Ryan Tannehill, a 25 percent chance of drafting Morris Claiborne, a 25 percent chance of drafting Trent Richardson, and a 15 percent chance of drafting Justin Blackmon. Now imagine that there is a 0 percent chance that any team between the Browns and the Dolphins would take Tannehill, but that the Dolphins had a 90 percent chance of selecting Tannehill if available. If our goal was to project the Browns’ and Dolphins’ most likely pick we would give them both Tannehill.

Because I was not so bold to throw internal logic to the wind, I designed the Mocktopus to eliminate the doubles and replace them with highly-rated players with uncertain destinations.

In making these decisions, the Mocktopus optimizes its mock draft to score as highly as possible under the scoring system popularized by the website the Huddle Report: two points for a player correctly matched to the team that drafted him and one point for correctly slotting a player in the first round.

I can only speculate on how accurate the mock drafts produced by the Mocktopus will be. Although there have been 223 first-round picks made in the time period we analyzed to create the Mocktopus (2005–2010), those sample sizes are a lot smaller when you drill down on a position by position basis (only eleven interior linemen drafted). The Mocktopus is also prone to human and computer error. The Mocktopus relies on a large amount of data that changes fast and often, and moreover, I’m a new hand at computer programming and have been snuffing out bugs in the program up to the last minute. So, the Mocktopus is far from a finished project—hence the beta moniker. Think of it as a fun experiment that we’re putting out a little early rather than keeping it under a rock.

1. Indianapolis Colts / Andrew Luck, QB, Stanford

No analysis necessary here. The Mocktopus would give Luck to the Colts anyway, but his selection is so certain that I locked him in.

2. Washington Redskins / Robert Griffin III, QB, Baylor

Ditto.

3. Minnesota Vikings / Matt Kalil, OT, USC

Kalil appeared here in almost everybody’s mock draft—until yesterday, when drafntiks finally started to become convinced that the Vikings might take Claiborne. The Mocktopus still likes Kalil here.

4. Cleveland Browns / Trent Richardson, RB, Alabama

There has been some late movement towards Justin Blackmon, but the Mocktopus prefers Richardson for this spot for a couple of reasons. First, the Mocktopus considers Richardson a better value than Blackmon. Second, mock drafters have traditionally had a much harder time projecting wide receivers than running backs, so the Mocktopus weighs the votes for Richardson a little heavier than the votes for Blackmon. A Blackmon selection, however, is entirely possible and would really shake up the top six, which until recently, looked almost set in stone.

5. Tampa Bay Buccaneers / Morris Claiborne, CB, LSU

The Mocktopus likes Claiborne here, but would strongly favor the Buccaneers to jump on Richardson if he falls.

6. St. Louis Rams / Justin Blackmon, WR, Oklahoma State

The choice here seems to be between Blackmon and Claiborne. The Mocktopus thinks there is only about a six percent chance that Trent Richardson drops and the Rams take him. Also, Claiborne instantly becomes the favorite if the Browns take Blackmon.

7. Jacksonville Jaguars / Melvin Ingram, DE, South Carolina

Mock drafts have been mocking an edge rusher to the Jaguars for years but they haven’t taken one high since the Derrick Harvey experiment.

8. Miami Dolphins / Ryan Tannehill, QB, Texas A&M

Aside from Luck and Griffin, Tannehill is the Mocktopus’s biggest lock of the draft by far. Why? First, the mock drafts are nearly unanimous. Second, there is a huge gap between Tannehill and the next most highly rated player of his position group, Kirk Cousins.

9. Carolina Panthers / David DeCastro, G, Stanford

This is a four-man race between Fletcher Cox, Quinton Coples, Justin Blackmon, and David DeCastro (in that order). Fox, Coples, and Blackmon, however, each appear in a few more simulations for other teams, so DeCastro, a highly rated player who is hard to find a home for, goes here.

10. Buffalo Bills / Luke Kuechly, LB, Boston College

The Mocktopus thinks that Luke Kuechly, who it values as the seventh best player in this draft, would be a great value pick over the flashier pick, Michael Floyd and the dark horse, Mark Barron.

11. Kansas City Chiefs / Mark Barron, SAF, Alabama

A few days ago Barron looked like a lock to go to the Cowboys at number 14, but some late movement in the mock drafts and an increase in his perceived value moves him up to the 11th pick. He edges Stanford guard David DeCastro by the slimmest of margins.

12. Seattle Seahawks / Quinton Coples, DE, North Carolina

The conventional wisdom for this pick is that the Seahawks could use a pass-rushing threat on the other side of Chris Clemons, and that Pete Carroll is such a great motivator that he can get the best out of Coples.

13. Arizona Cardinals / Riley Reiff, OT, Iowa

This pick likely comes down to whether the Cardinals prefer Reiff or Cordy Glenn. Reiff gets a decent edge because he has an advantage in both the mock drafts and the value charts. A dark horse could be Mark Barron, who would be considered great value if he slipped.

14. Dallas Cowboys / Michael Brockers, DT, LSU

The mock drafts still favor Barron for the Cowboys, but his value is so high he is unlikely to slip to the Cowboys. The Mocktopus gives the Cowboys an almost 75 percent chance to draft Barron if he is available, but he was only available in just under 25 percent of simulations.

15. Philadelphia Eagles / Fletcher Cox, DT, Mississippi State

There are rumors that the Eagles covet Cox so much that they could trade up to take him. Although the Mocktopus does not yet have the capacity to project trades, it nevertheless thinks that Cox has a strong chance to end up here because if others pass on him, the Eagles are a great candidate to snatch him up.

16. New York Jets / Courtney Upshaw, OLB, Alabama

If Courtney Upshaw tops 18.0 sacks in his first two years, he and Jason Pierre-Paul can meet up at some fancy New York restaurant and drink champagne and go all 1972 Miami Dolphins at my expense.

17. Cincinnati Bengals / Dre Kirkpatrick, CB, Alabama

The Bengals need a cornerback, and Stephon Gilmore’s late rise suggests that Kirkpatrick will be the best option here.

18. San Diego Chargers / Whitney Mercilus, OLB, Illinois

Since Larry English was a bust, the Chargers have to try again.

19. Chicago Bears / Chandler Jones, DE, Syracuse

The late-rising Chandler Jones is likely to go in the first-round, and the Bears could use pass rush help, so it’s a decent enough fit.

20. Tennessee Titans / Stephen Hill, WR, Georgia Tech

There will probably be lots of good options here. The Mocktopus is pretty evenly split between Hill and the Titans breaking the fall of a number of players that are not generally expected to be here, like Stephon Gilmore or Melvin Ingram.

21. Cincinnati Bengals / Dontari Poe, DT, Alabama

This is where chaos theory really takes hold and the Mocktopus starts spitting out low probability projections. Poe is the leader to go to the Bengals here and he does so in only 800 simulations out of 10,000.

22. Cleveland Browns / Kendall Wright, WR, Baylor

Wright has been here since there was talk of the Browns taking Robert Griffin III at fourth overall. Wide receivers are hard to project, but the Browns are as likely to take a wideout as anyone.

23. Detroit Lions / Michael Floyd, WR, Notre Dame

Did somebody let Matt Millen into the building? Nah. The Lions are just hard to mock and Floyd is hard to place because he keeps coming out on the losing end of narrow battles for spots in the upper-to-mid first round. Glenn may actually be the most likely option for the Lions here, but he shows up on the next team in more of our simulations.

24. Pittsburgh Steelers / Cordy Glenn, OT, Georgia

The Mocktopus wants to give the Steelers Dont’a Hightower or one of the tackles.

25. Denver Broncos / Jerel Worthy, DT, Michigan State

The Mocktopus likes Worthy to go to the Broncos because, for some reason, the mock drafts have formed a consensus around Worthy and the Broncos despite the logjam of interior defensive linemen in this draft.

26. Houston Texans / Coby Fleener, TE, Stanford

The Mocktopus likes Fleener to the Texans more than any other pick at the end of the first round. Why? Mock drafts historically rack up points for where they project tight ends—and some good ones have Fleener going to Houston—while Rueben Randle, the other favorite of the mock drafters, would not be good value here.

27. New England Patriots / Nick Perry, OLB, USC

This pick could work because Perry can bring the heat off the edge and has the size that the Patriots covet in their outside linebackers.

28. Green Bay Packers / Shea McClellin, OLB, Boise State

There is a solid mock draft consensus consolidating around McClellin to Green Bay. Despite the cluster of similarly valued edge rushers at the end of round one, and all of the craziness that can happen between picks 3 and 27, the Mocktopus puts the chances of McClellin going here at a healthy 37.3 percent.

29. Baltimore Ravens / Dont’a Hightower, ILB, Alabama

The collection of 3-4 teams at the end of round one gives Hightower a great chance of hearing his name called on Thursday night.

30. San Francisco 49ers / Kevin Zeitler, G, Wisconsin

This is a close race between Zeitler and Amini Silatolu.

31. New England Patriots / Stephen Gilmore, CB, South Carolina

This would be a great move for the defensive back-starved Patriots, but unfortunately, Gilmore is unlikely to last this long. The Mocktopus just thinks that the Patriots are so unpredictable that it’s better off placing someone who is almost certain to go in the first round somewhere. Given the Patriots’ drafting history, that’s probably a smart move.

32. New York Giants / Jonathan Martin, OT, Stanford

This is a pretty big slide for a player who has been hyped as having the athleticism to play left tackle. The Mocktopus likes the Giants to break his fall at a pretty high clip—he appeared here in 23.2 percent of simulations.

Posted by: Guest on 26 Apr 2012

59 comments, Last at
03 May 2012, 11:02am by
chemical burn

Comments

Kind of a weird result. The desire to match players being projected to go in a place means that you have a mock that ranks players out of order (presumably). For example, Kirkpatrick goes before Gilmore and Stephen Hill goes before Michael Floyd. In all likelihood, if any team is making that choice they probably go the other way.

But if I understand the method, it's trying to get the highest score. So it says, "well, Floyd (for example) will be gone by 20 so the Titans will take Hill as their WR. But we don't know where Floyd will go above 20. If we put Floyd at 20 and Hill somewhere later we'll miss on 2 picks and get 0 points. If we at least get the Hill pick right that's 2 points". So, you end up with a possibly accurate but illogical mock draft. It'll be interesting to see how it does.

I'm curious, what were the mock draft sources? Was it only professionals, or did you take any of the more amateur drafts as inputs, like the ones you find linked on Hail Redskins?

Well let me expound, I think you made a mistake by having a single player listed for each team. It would be much more interesting to see every player above a certain percent chance to be picked (5%, 10%, something like that) listed for each team. I would prefer to see the Bears have a 40% chance at drafting player A, and a 30% chance to draft either player B or C, than player A is the most likely pick, but there is a bigger chance they won't take him.

I agree. The article is losing a lot of the value of its data-crunching by presenting things in standard mock format. It would be better to have a list of players for each team, sorted by the probability that they'll draft him. And in parentheses, the probability that they'll draft the player if he's available.

It would also be interesting to see it organized by player. For each player, what's the 90% confidence interval on when he'll be drafted, and who are the most likely teams.

Yep, those are all ideas that Nathan is playing with for next year. I've already considered an application on FO similar to the ESPN NBA Draft Lottery application, where you can hit a button and find out what players are mostly likely to still be available at pick X, or what players are most likely to be taken at pick X, or what teams are most likely to take player X. We've got a lot of ideas.

Mostly, I wanted to get up this "Beta test" version because I love the name so much. Mocktopus!

I want very much to like this, but I'm a little puzzled. How is this not simply aggregating the most popular mock drafts and then spitting out a (somewhat) consensus result?

It reminds me of Wisdom of Crowds. My issue there is that I don't care what the crowd thinks. I care what the teams think.

I think this could have a lot more value if it factored history into the equation. What is the philosophy of that particular team? For example, we know the Giants historically take "safe" picks in the first round - guys from major schools who had productive college careers. We have history to show us that certain teams (or coaches and GMs) count character more and certain teams count it less. A computer simulation that incorporates that data sounds much more valueable to me than simply plugging in the results of a bunch of mock drafts.

Unless your team is the Dolphins, Jaguars, Browns, Bengals, or (until recently) the Raiders, then the answer is no you don't. Any team that takes Andre Smith or Mike Mitchell in the first two rounds is crazy.

Haha! No, I'm saying I don't want to know what goes on in some draft rooms.

For example, take the Eagles. They soooooooo need a decent Linebacker, but they looove linemen. It's almost some NFL agent plays the siren song of Linemen and they can't resist. Last year they took Danny Watkins. Before that they took Brandon Graham when Earl Thomas was on the board. SMH.

OK. I was pretty sure my snark detector was broken, but I couldn't figure out where you were going with it. Here's the thing, though. We know that about the Eagles and yet we STILL never know what's going to happen with them. As a draft geek who loves to prognosticate, that's exactly the sort of info I would want plugged into any simulation - even, hell especially, if it makes me pull my hair out.

I actually have a litnus test for mock drafts. I scroll to the Eagles first round pick. If it's a linebacker, I know not to put any stock in that particular mock and I don't have to waste my time reading the rest.

If Cox (Eagles ultimate target, not a secret anymore IMO) is not available and Kuechly is at 15, that will be the ultimate test about LBs/Andy Reid era. Can't remember a prospect matching what the Eagles want (leadership, production, effort) more than him in recent years.

The only LB I was screaming for the Eagles to take recently was David Harris back then, when they ended up taking Kolb. Since then, I've never seen a slam dunk prospect like Luke Kuechwalker.

I don't know - they just spent a lot of money at LB and have really young guys they like or at least want to try to develop. I think LB is entirely off the table. This mock draft seems about right, although (as always) I can see them trading down to do something nuts (like trying to get a discount on a falling Gilmore) or trying to work up to the top of the second round to take a QB.

1) I don't for one second buy the Fletcher Cox story. Since when do the Eagles EVER have their draft day intensions leak out like that?

2) I don't think Kuechly will be there, but if he is, I would expect the Eagles to pass. I would be STUNNED and I don't mean that in a sarcastic manner in the least. Even if Reid were to move down and even if Kuechely were the faller of the draft, I STILL would be stunned if the Eagles got him at 32. It's just not how they do business.

I just looked this up because off the top of my head I could not remember the Eagles taking a linebacker high at all recently. Here are all of the linebackers taken by the Eagles in the Reid era: http://pfref.com/tiny/osp0p

I am not posting this to argue against or for anyone's points or to make any particular point of my own. I just thought someone else may be interested since I was.

Ugh - Matt McCoy was a second rounder? The worst Eagles' starter of the decade (well, either him or Mike McMahon) was somehow even worse of debacle than I imagined - I just assumed he was a street free agent forced into the line-up...

Also, am I crazy or does it look like Reid got burned by Caver and Gardner (who were both terrible) early in his tenure and decided drafting LB's high wasn't the best use of resources?

My understanding was that Reid's reluctance to commit resources to the LB position stems from the success Jimmy Johnson had in the 90s, albeit from a distance. The difference, of course, is that Johnson was able to get inexpensive options who proceeded to play at a high level.

I was disappointed by the McCoy pick while his teammate Kirk Morrison was still on the board, and looked better. I then had some hope in his 2nd (or 3rd?) season where he looked athletic and like a good hitter... But then teams were running right at him for huge gains constantly, which made his replacement Akeem Jordan look like a star in comparison. Well...

Pick 46 is super early for a LB for Eagles. But while I really liked what I saw from him pre-draft, I'm not a huge fan of the pick for the them - He looks like an attacking player, blitzing and even lining up at 7/9 tech on passing downs, which is NOT what the Eagles do anymore.
Now Mike/Sam LBs in the wide 9 are like ILBs in a 3-4, they are playing inside, need to be physical, shed blocks and tackle well (Kuechly). Doesn't look like a Kendricks type of LB (despite 20 experts saying he will fit the "aggressive" style of play of the eagles defense, which was true previously, but not anymore, at all).

Chemical, unlike you I'm a huge fan of the Cox pick. In fact overall that is the best draft I've seen by the Eagles "on paper" ever (=10 years for me).

I'm actually more of a fan of the Cox pick because of the Kendricks pick. Plus, I've been thinking about their defensive situation in light of letting go of Samuel and picking up DeMeco Ryans - I do think there's a bit of a sea change going within the organization in terms of defensive philosophy and I think 2012 will be the first year since he died where they aren't trying on some level to imitate Jim Johnson (wisely, I think, because he's inimitable.)

It looks like they want small pass-rush-oriented d-linemen to jump off the line and disrupt the point of attack, rather than Johnson's rigid commitment to gap-discipline and back of the play responsibilities. But if they're going to do that they need run-stuffing, attacking LB's like Kendricks (and I've heard mixed reports, but many folks are saying he's a tough, physical player, not a finesse guy) and Ryans to shore up the running game - they need guys who blow through blocks and pound the ball-carrier (i.e. not Simoneau/Fouku/Dhani types) They also can't really afford to have a tiny CB who frequently injures himself just by attempting to tackle, they're just banking on the second-level being more involved in the running game I think and going to man/press with Asomugha and DRC would be part of that - their CB's need to be able to get off their blocks or otherwise gum up the running game.

If Cox is the Warren Sapp-esque inside playmaker a lot of folks are saying he is, then having him next to Jenkins will be pretty awesome - the LB's will just have to be able to back them up and get dirty, which obviously a Matthews/Fouku/Rolle/Jordan type set of backers would be terrible at (and were last year.) The question to me is how Brian Rolle and Nate Allen end up factoring into this because they've proven themselves to be poor open-field tacklers. But the WILL and FS being bad at tackling probably isn't the end of the world...

Anyway, I think they have a plan, is what I'm saying and Cox will factor positively into it...

So the model determines which position a team will draft, then picks the player at that position? That makes sense for teams that draft for need, but don't most GMs claim that they'll just draft the best player available? I wonder if there's enough historical draft data to let us figure out a GM/front-office tendency to draft for value versus need...

Also, the sentence "The principal components in the Mocktopus are other mock drafts." confused me a bit because I thought you were doing PCA, but it turns out that you just meant that "The main inputs to the Mocktopus are other mock drafts".

Yeah, Rick Smith invariably preaches the gospel of BPA, but knowledgeable Texans-watchers will always be able to identify at most two or three positions on which the first round pick could be used, and do a fair job on which positions are likely to be addressed later. This year, the first round pick was always going to be either a pass rusher (which it was) or a wide receiver (at which position they spent their next pick and a fourth rounder), with offensive linemen (three picks in total) and a kicker (fifth round) likely to come later. Trying to identify the specific players tends to be much harder, because they appear to diverge significantly from consensus in the way they assess players (evidently they didn't think Randle was much better than Posey, for example).

The closest to a true BPA strategy I've ever noticed was from Denny Green, who I'm not sure actually used scouts or considered position - he just seemed to draft the highest player left on Gosselin's mock.

I think for the most part BPA tends to be code for doing the responsible thing and considering the quality of the player compared with the quality of players at other positions in addition to considering your team's current roster and projected roster over the next couple of season as contrasted with picking the best at position X come hell or high water.

I think that is more or less it but I think you can still do BPA and target players.

If there is a player you want, but it would be a reach to get them where you are in the draft you trade back and then you take them later. Or you trade up to get them in the spot where they are very likely to go. Both times they are the best player available, but the team is matching the spot to the player not the player to the spot.

Of course you can't always find a trading partner and being able to hit the right spot so that you turn your spot into the one where that player is now the best on the board. That's when you have to go, OK, the best player regard less of position is X, but the player that will best help our team is Y and they are only the 5th, or 6th or 10th best overall. Most teams if it's close enough are taking the player best able to help the team, but sometimes you pick Aaron Rodgers even if you figure he will be sitting on the bench for 3 years and you really need a linebacker or wide receiver or whatever.

Yeah BPA does really seem to only apply in the first 3 rounds or so, after that talent difference are a lot smaller. Sometimes you get major talents that fall to the 4th with character issues or injury issues, but then you are adding that major red flag that has to be factored.

There are occasions when a guy that one team has rated a lot higher than other teams keeps falling, and the team that likes him has to decide whether to ignore needs and take their highly-rated player.

Although mock drafts are frequently criticized for missing on their picks more often than they hit, they are nevertheless significantly more accurate than a chimpanzee pulling random names out of a hat.

Do you have any research to back up this claim? More importantly, does the Mocktopus factor in the statistics of incoming free agents? Does it consider the amount of money invested in a given position?

I'm really excited to get into the chat and read your comments, but I've been working really hard to get all of the late-breaking updates into the Mocktopus to get what should be the official result. I had some issues with the optimizer, so I fixed the doubles by hand. I'm starring the new entrants so you can see the changes. Here it is:

But wouldn't that give them a decent looking 4-3 line with Wilfork and Brace inside and two edge rushers to complement them? You can also be pretty certain that the Pats will make some sort of trade anyway, I'd be astonished if they picked in those two spots.

That looks like a pretty decent mock. I'm just sad that it didn't involve any octopi picking different prospects' pictures to get at a tasty clam inside. You'll just have to work on that for next year.

Although a Nick Perry/Chandler Jones combo would indeed be scary, Chandler Jones is a strategic pick. Jones is the runner up to go in the 27 spot, and there is no clear favorite at 31 (Harrison Smith comes the closest). So by mocking them both to the Patriots you really hedge your bets on a position where the Patriots are likely to go(seriously, getting any expected value out of mocking players to the Patriots is a win). Plus, Chandler Jones is another one of those guys who is likely to go first round but hard to slot.

Re "this project has also raised an oddly philosophical question about mock drafting: what is the purpose of a mock draft?"

Indeed, I've been wondering about this for a long time, both as I think about why my team will actually be doing and about how much I trust various draft "experts" with their assessments of who good a certain player is.

Obviously, when you go back and try to compare who a team drafts in the first few rounds with what experts think they will draft, you rarely come up with anything close to correct. This is due in large part because teams trade up and down on draft day-- if a team X is sitting at a spot S, you can consider needs and the best player to fill that need that fits spot S and make some assumptions about that and predict player alpha. But if team X moves up a number of spots to G or F, then player alpha no longer makes sense. But mock-drafters have no way of prediction such movements.

Thus perhaps there's a correlation between what spot in the draft a certain player is projected to go, maybe with a +/- 1 or 2. But even then, after the first few spots, things start to fall through. For example, let's say that of the teams drafting in spots 11-20, all are set at a certain position except for the team at 15. Mock drafters thus project that the team at 15 takes a certain player who is rated very high and fills that need. But if team 15 moves up (or down) by quite a bit, that player who was projected to go at 15 may drop down to 21 or 22. (Ironically, they might even fall to the team originally projected to take him, but 7 spots later in the draft!)

Here are what various USA Today "experts" predicted for the draft. (I'm fairly sure they all just bought some draftnik stuff with their USA Today expense account and cribbed out of those.) After the first two picks-- which everyone knew-- it gets screwy. Of the 5 mock drafters, all 5 had CLE taking Richardson, but they had them taking him at #4, not #3. Still, that's a win for them, I guess. Similarly, 4 of 5 had MIN taking Kalil. That's more or less a win for them, too.

It gets slightly worse after that. No one had Blackmon going at #5, and 4 of the 5 had him going to STL (at #6), while only one had him going to JAX (at #7). Still, if we allow for a +/-2, these guys are doing OK. Continuing, 4 of 5 had Claiborne going to TB at #5. But Claiborne ended up going to DAL at #6. Wrong team, but more or less in the same spot.

After that, though, it gets worse. In real life, TB took Barron at #7. However, 4 of the 5 mock drafters had Barron going to DAL at #14 (the other had him going #10 to BUF). Then it gets normal-- MIA acted as predicted by all 5 mock drafters.

At this point, it gets too complicated to narrate. The mock drafters start to deviate from each other in varying amounts so that it's hard to gauge the point. CAR drafter a ILB in real life at #9, but the mock drafters had them drafting a DT (4 of 5) or a CB (1 of 5). The DT ended up going to PHL at #12, but the CB did go at #10. Mock drafters had BUF's #10 go to a T, a ILB, a WR, and a S.

I could go on, but as I said, it gets complicated.

All of this is to say that I think that mock drafts really don't seem to serve any purpose except as some sort of football fix/anxiety relief for hard core NFL fans. After the first 10 or so picks, there seems to be little bearing on reality either for the position a player gets drafted, or for who a team will go for. Indeed, it seems hard to predict which direction a team will go. Offense? Defense? DL? LB?.

Moreover, because teams have their own internal scouting, it is hard to even just line up a prospect's grade with where they'll go. For instance, NFL.com has OG Luke Nix grading out at 74.5, yet he went undrafted, while OGs who were grading out in the mid 40's went in the 6th round. Obviously, something isn't right, else this guy would have gone much higher.

So while I like the draft as a concept, it's hard to me to get much out of it. I'm not an expert in college player evaluation, so it's hard for me to think that the drafting of player X or Y is good. I do have some sense of my NFL team's needs, so I can be vexed when my team doesn't seem to fix those needs, but that's about it.

All that assumes the the mock draft is in some way intended to be predictive. Surely in some way these are supposed to be prescriptive to some degree or another. I've also seen retrodictive mocks, which are pretty easy to identify.

Well, perhaps. I've never seen a mock draft described as "this is whom I think team X should draft" as opposed to whom they will draft, but perhaps they should do so. After all, when it comes to on-the-spot critiques, it's always based on the former.

The retro drafts are silly, since there's no way to know that Player X would do as well for Team B as he did for Team A. One imagines that if Tom Brady were taken by Cleveland or Oakland, he'd have washed out after a few years and would now be selling insurance in northern California.